Chasing the Wind

I have a feeling that, despite the concerns regarding the cap, Sunday will be the better of the two days (as Jeff has said, “the day before the day”). Admittedly, convective initiation before sunset is a bit more uncertain due to the apparent lack of forcing for convection, but I've seen enough to know that these concerns are usually based on lack of information rather than potential. In other words, we probably won't know if convective initiation will occur until probably the 20-23 Z time frame (i.e., when TCU actually start to develop). Several other days in the past featured similar doubts regarding initiation, and due to factors beyond our real-time observation abilities, were able to produce. Days that come to mind are: May 12, 2004 and of course, May 3, 1999. Granted, it could just as easily cap bust, but I strongly doubt it will.

First, I like the increasing flow over the mountains; this is a feature that is often present with regional outbreak events. This should enhance the strength of the lee trough such that the near-surface winds will pick up in a hurry. Should upper-flow be any stronger than progged (a la, May 3rd), this process should commence faster and lead to the potential for daytime supercells (since convergence along the dryline would be increased via downward mixing of westerly momentum behind the dryline). Also, I really like the strong moisture advection. Adding a few g/kg to the mixing ratio does wonders to increase CAPE and remove any remaining convective inhibition.

Overall, I'm very pleased with the setup, and I think at least a few tornadoes are likely on Sunday.